Context

• Most research on seismic and landslide hazards in the Himalaya focus on geophysical and geomorphological characteristics.

Key Details

• A study by the Scientists from Wadia Institute of Himalayan Geology, Dehradun an autonomous institute under the Department of Science and Technology (DST), Govt. of India suggests that, unlike other parts of the western Himalaya, in Kumaun, partial melting of the crust is caused by activation of a tabular to sheet like, planar or curvi-planar zone composed of rocks that are more strained than rocks adjacent to the zone (major shear zones), instead of continuous zone of mid-crustal partial melts.
• shows inverted metamorphism (condition in which higher-grade metamorphic rocks lie on top of lower-grade rocks), leading to partial melting of the Himalayan crust in two short spans.
• one uniform mechanism cannot explain the evolution of the Himalayan metamorphic core.
• Activation of major thrusts and different mechanisms may operate at different cross-sections of this orogeny with channel flow (long-lasting flow of a weak, viscous crustal layer between relatively rigid yet deformable bounding crustal slabs) being dominant in the hinterland, and at ductile regime.

Back to Basics

Kumaun Himalaya

• It lies largely within the state of Uttarakhand and northwest of Nepal.
• The Kali River Valley of Kumaun marks the international border between India and Nepal.
• This region experiences intense seismic and landslide events.

• The range includes the Siwalik Range in the south and part of the Great Himalayas in the north.
• Lies between Sutlej River in the east and the Kali River in the west.
• Nanda Devi, the range’s highest peak.
• Glaciers and snowmelt feed the headstreams of the Ganga River.
• Deodar, cedar forests are found here.

Source: PIB